Apparatus for supplying cooling channels of rotors of electrical machines with cooling waters

ABSTRACT

With hydrogen enrichment of the cooling water and palladium catalyst in the cooling water circulatory loop from the leakage water chamber of a cooling water connection head, the leakage water chamber is also connected to a source of hydrogen gas. Sufficient saturation of the leakage water with hydrogen is accordingly effected prior to the admission thereof to the palladium catalyst. Furthermore, removal of the gas by suction is effected through an after-connected gas suction chamber.

United States Patent Pluschke 1 Nov. 25, 1975 APPARATUS FOR SUPPLYING COOLING CHANNELS OF ROTORS OF ELECTRICAL MACHINES WITH COOLING WATERS 3335.9) 9/1974 Lambrecht et a]. 165/47 Primary Examiner-Albert W, Davis. Jr Attorney, Agent, or Firm-Herbert L. Lerner [57] ABSTRACT With hydrogen enrichment of the cooling water and palladium catalyst in the cooling water circulatory loop from the leakage water chamber of a cooling water connection head, the leakage water chamber is also connected to a source of hydrogen gas. Sufficient saturation of the leakage water with hydrogen is ac cordingly effected prior to the admission thereof to the palladium catalyst. Furthermore, removal of the gas by suction is effected through an after-connected gas suction chamber.

3 Claims, 1 Drawing Figure U.S. Patent Nov. 25, 1975 APPARATUS FOR SUPPLYING COOLING CHANNELS OF ROTORS OF ELECTRICAL MACHINES WITH COOLING WATERS The invention relates to apparatus for supplying cooling channels of rotors for electrical machines with cooling water.

In my U.S. Pat. No. 3,7l 1,731, issued Jan. 16, I973, l have disclosed apparatus of the foregoing type which has been especially provided for turbogenerators with directly water-cooled rotor windings. The apparatus of my aforementioned patent includes an inlet chamber surrounding the shaft of the rotor in liquid-tight relationship to the ambient, an outlet chamber communicating with the rotor cooling channels for receiving the cooling water, the latter being heated and reduced in pressure by its passage through the rotor channels, the outlet chamber surrounding the rotor shaft in liquid tight relationship to the ambient, primary conveying means connected between the outlet chamber and the inlet chamber for conducting the water between the outlet chamber and the inlet chamber; pump means for supplying the cooling water to the inlet chamber under pressure and for urging the same through the primary conveying means; a leakage water chamber next to the outlet chamber in a direction toward the ambient, the leakage water chamber having a first contactless seal disposed with respect to the shaft where the leakage chamber adjoins the ambient and a second contactless seal where the leakage chamber adjoins the outlet chamber, the leakage chamber serving to collect cooling water which leaks through the second seal during normal operation, the cooling water being mixed with air leaking into the leakage-water chamber from the ambeint, the pump means communicating with the leakage-water chamber for drawing the leakage cooling water from the leakage chamber, hydrogen gas supply means connected to the conveying means for saturating the cooling water conveyed by the latter with hydrogen, and an oxygen removal device for receiving the leakage water mixed with air, the device being con nected between the leakage water chamber and the primary conveying means. In a more specific embodiment of the invention in my aforementioned patent, the oxygen removal device is provided with palladium catalyst.

The saturation of the cooling water with hydrogen gas, which is effected in a water storage tank serving as a water expansion vessel, by the introduction of hydrogen gas thereto, is necessary to attain a remainderless or stoichiometric conversion or combination of the ox ygen in the water with the dissolved hydrogen to form additional water in the palladium catalyst. It has been found, however, that the hydrogen content in the water is not always sufficient so that oxygen penetration behind or upstream of the palladium catalyst occurs.

it is accordingly an object of the invention of the instant application to provide apparatus of the aforementioned type which is improved over that disclosed in my aforementioned patent so that the cooling water always contains enough dissolved hydrogen as to afford a complete conversion in the palladium catalyst of the oxygen dissolved in the water by the chemical combination of all of the oxygen with the hydrogen to form additional water.

With the foregoing and other objects in view, there is provided in accordance with the invention in an apparatus for supplying cooling water to the cooling chan- 2 nels of an electrical machine rotor having a rotor shaft, an inlet chamber surrounding the rotor shaft in liquidtight relation to the ambient, an outlet chamber communicating with the rotor channels for receiving the cooling water, the latter being heated and reduced in pressure by its passage through the rotor channels, the outlet chamber surrounding the rotor shaft in liquidtight relation to the ambient, primary conveying means connected between the outlet chamber and the inlet 0 chamber for conducting the water between the outlet chamber and the inlet chamber; pump means for supplying the cooling water to the inlet chamber under pressure and for urging the same through the primary conveying means; a leakage water chamber next to the outlet chamber in a direction toward the ambient, the leakage water chamber having a first contactless seal disposed with respect to the shaft where the leakage chamber adjoins the ambient and a second contactless seal where the leakage chamber adjoins the outlet chamber, the leakage chamber serving to collect cooling water which leaks through the second seal during normal operation, the cooling water being mixed with air leaking into the leakage-water chamber from the ambient, the pump means communicating with the leakage-water chamber for drawing the leakage cooling water from the leakage chamber, hydrogen gas supply means connected to the conveying means for saturating the cooling water conveyed by the latter with hydrogen, and an oxygen removal device for receiving the leakage water mixed with air, the device being connected between the leakage water chamber and the primary conveying means; the improvement therein comprising means connecting the hydrogen gas supply means to the leakage water chamber, and a gas suction chamber next to the leakage water chamber in direction toward the ambient, the gas suction chamber being connected through a blower to a waste gas line.

Due to the fact that the leakage water chamber is now directly supplied with hydrogen gas, the partial pressure of the hydrogen in the gas mixiture there present is increased and provides the prerequisites for reliable functioning of the palladium catalyst due to the constant presence of the hydrogen excess, so that assurance of minimal oxygen remainder in the cooling water is afforded.

In accordance with another feature of the invention, the primary conveying means includes a water storage tank having a water-containing space and a gas space therein, the leakage water chamber also having a leakage water-containing space and a gas space therein, and including a line mutually connecting the gas spaces of the water storage tank and the leakage-water cham ber.

Other features which are considered as characteristic for the invention are set forth in the appended claims.

Although the invention is illustrated and described herein as embodied in apparatus for supplying cooling channels of rotors of electrical machines with cooling water, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.

The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying single figure of the drawing which is a schematic view of the apparatus of the invention for supplying cooling water to the cooling channels of an electrical machine rotor.

Referring now to the drawing, there is shown therein diagrammatically an electrical generator 1 having a stator 2 and a rotor 3. The rotor 3 has a shaft end 3b surrounded by a stationary cooling water connection head 9 formed with a suction chamber K2, which annularly surrounds the shaft end 31) and from which water is sucked by a shaft pump 7 firmly connected to the shaft end 319 into a pressure chamber Kl also annularly surrounding the shaft end 3b. The cooling water is fed from the pressure chamber Kl through an outer circuit 1 in which a cooler W and a filter F is connected to a stationary inlet tube 8 having a central bore 80, from which the cooling water is passed into a central bore 6a formed in the rotor shaft and 3b. The cooling water then flows in the direction indicated by the associated arrows in the figure through the coils of the rotor winding and through a discharge channel 6b coaxially surrounding the inlet channel or bore 6a into an outlet chamber K3 formed in the cooling water connection head 9 and coaxially surrounding the shaft end 3b. The water flows from the outlet chamber k3 through a line 1, into a water storage tank 11, which serves as a water expension tank, and from the latter through a return line 1,, back into the suction chamber K2.

A leakage water chamber K5 is connected to the outlet chamber K3 downstream thereof as viewed in direction toward the ambient, through a pressure equalizing chamber K4 that is also filled with cooling water. The leakage water chamber K5 is followed by a gas suction chamber K6 downstream therefrom toward the ambient and having virtually the same level of pressure therein as the leakage water chamber K5. All of the shaft seals of the individual dividing walls or partitions between the chambers Kl to K6 are constructed as contactless shaft seals w.

In order to prevent oxygen, which penetrates from the outside or develops within the coolant circulation loop and dissolves in the water, from causing corrosion in the coolant circulatory loop, a palladium catalyst is inserted into the cooling circuit to convert the air oxygen. To afford such catalysis, a given excess of hydrogen is always required, however. For this reason, the cooling water circulatory loop is connected to a gas source which saturates the cooling water with hydrogen gas; and the water storage tank 11 serving as a water expansion vessel and disposed in the upper part of the stator 2 of the electric machine above the level of the water connection head 9 and provided with a gas space llb containing hydrogen gas and forming a pressure gas cushion located above a water-containing space lla, is in fact used for the foregoing purpose. The hydrogen gas H,, as indicated by the associated arrow, is introduced from an otherwise nonillustrated gas source through a gas supply line 1,, into the gas space llb at one end thereof and discharged at the other end thereof through a gas discharge or suction line 1, A constant hydrogen flow is thereby attained in the gas space llb so that the water is brought into intimate contact with the hydrogen gas which is continually dissolved therein so that the water is saturated with hydrogen gas.

The required palladium catalyst 15 is inserted in an adjacent branch of the coolant circulatory loop and, in fact, in a line 1,, extending from the leakage water chamber KS. The molecular binding forces of the hy- 4 drogen gas become neutralized in the catalyst 15 so that the hydrogen in atomic state combines at relatively low temperatures with the oxygen dissolved in the water to form additional water. The additionally formed water is returned through the pump 16 to the water storage tank 11 or to the return line 1, extending from the outlet chamber K3.

A given excess of hydrogen is always required for the conversion in the catalyst to be effected so that largely all of the oxygen dissolved in the water will always be converted. it has been found, however, that rinsing of the water space lie with hydrogen gas alone is not always sufficient to maintain the required saturation of the water with hydrogen, so that oxygen penetration can occur behind or upstream or the catalyst 15. For this reason, it is provided, therefore, that the leakage water chamber K5 is also connected to a hydrogen source. As can be seen in the figure of the drawing, the suction line 1,; extends from the water storage tank 11 directly into the leakage water chamber K5. Suction is then effected through the adjacent gas suction chamber K6 from which the hydrogen gas passing over thereto from the fission water chamber K5 through the liquidtight seal therebetween together with air sucked in through the liquid-tight closing shaft seal wa is advanced through a connecting line 1 and a blower 17 into a waste gas line 18 of the system.

This constant or continuous hydrogen gas flow through the leakage water chamber K5 increases the partial pressure of the hydrogen in the gas mixture present therein, which is essentially freed from the leakage water that has passed over from the pressure equalizing chamber K4, and provides the prerequisites for optimal functioning of the palladium catalyst 15 due to the continuous presence of the hydrogen excess. Through this additional hydrogen enrichment of or concentration in the cooling water, strict assurance of an absolutely minimal remainder of oxygen in the cooling water is provided, so that danger of corrosion in the cooling water circulatory loop is largely avoided.

[ claim:

1. ln apparatus for supplying cooling water to the cooling channels of an electrical machine rotor having a rotor shaft, an inlet chamber surrounding the rotor shaft in liquid-tight relation to the ambient, an outlet chamber communicating with the rotor channels for receiving the cooling water, the latter being heated and reduced in pressure by its passage through the rotor channels, said outlet chamber surrounding the rotor shaft in liquid-tight relation to the ambient, primary conveying means connected between said outlet chamber and said inlet chamber for conducting the water between said outlet chamber and said inlet chamber; pump means for supplying the cooling water to said inlet chamber under pressure and for urging the same through said primary conveying means; a leakage water chamber next to said outlet chamber in a direction toward the ambient, said leakage water chamber having a first contactless seal disposed with respect to the shaft where said leakage chamber adjoins the ambient and a second contactless seal where said leakage chamber adjoins said outlet chamber, said leakage chamber serving to collect cooling water which leaks through said second seal during normal operation, said cooling water being mixed with air leaking into said leakagewater chamber from the ambient, said pump means communicating with said leakage-water chamber for drawing the leakage cooling water from said leakage 2. Apparatus according to claim 1 wherein the oxygen removal device includes a palladium catalyst.

3. Apparatus according to claim 1 wherein the primary conveying means includes a water storage tank having a water-containing space and a gas space therein, said leakage-water chamber also having a leakage water-containing space and a gas space therein, and including a line mutually connecting the gas spaces of said water storage tank and the leakage-water chamber. 

1. IN APPARATUS FOR SUPPLYING COOLING WATER TO THE COOLING CHANNELS OF AN ELECTRICAL MACHINE ROTOR HAVING A ROTOR SHAFT, AN INLET CHAMBER SURROUNDING THE ROTOR SHAFT IN LIQUID-TIGHT RELATION TO THE AMBIENT, AN OUTLET CHAMBER COMMUNICATING WITH THE ROTOR CHANNELS FOR RECEIVING THE COOLING WATER, THE LATTER BEING HEATED AND REDUCED IN PRESSURE BY ITS PASSAGE THROUGH THE ROTOR CHANNELS, SAID OUTLET CHAMBER SURROUNDING THE ROTOR SHAFT IN LIQUID-TIGHT RELATION TO THE AMBIENT, PRIMARY CONVEYING MEANS CONNECTED BETWEEN SAID OUTLET CHAMBER AND SAID INLET CHAMBER FOR CONDUCTING THE WATER BETWEEN SAID OUTLET CHAMBER AND SAID INLET CHAMBER, PUMP MEANS FOR SUPPLYING THE COOLING WATER TO SAID INLET CHAMBER UNDER PRESSURE AND FOR URGING THE SAME THROUGH SAID PRIMARY CONVEYING MEANS; A LEAKAGE WATER CHAMBER NEXT TO SAID OUTLET CHAMBER IN A DIRECTION TOWARD THE AMBIENT, SAID LEAKAGE WATER CHAMBER HAVING A FIRST CONTACTLESS SEAL DISPOSED WITH RESPECT TO THE SHAFT WHERE SAID LEAKAGE CHAMBER ADJOINS THE AMBIENT AND A SECOND CONTACTLESS SEAL WHERE SAID LEAKAGE CHAMBER ADJOINS SAID OUTLET CHAMBER, SAID LEAKAGE CHAMBER SERVING TO COLLECT COOLING WATER WHICH LEAKS THROUGH SAID SECOND SEAL DURING NORMAL OPERATION, SAID COOLING WATER BEING MIXED WITH AIR LEAKING INTO SAID LEAKAGE-WATER CHAMBER FROM THE AMBIENT SAID PUMP MEANS COMMUNICATING WITH SAID LEAKAGE-WATER CHAMBER FOR DRAWING THE LEAKAGE COOLING WATER FROM SAID LEAKAGE CHAMBER, HYDROGEN GAS SUPPLY MEANS CONNECTED TO SAID CONVEYING MEANS FOR SATURATING THE COOLING WATER CON-
 2. Apparatus according to claim 1 wherein the oxygen removal device includes a palladium catalyst.
 3. Apparatus according to claim 1 wherein the primary conveying means includes a water storage tank having a water-containing space and a gas space therein, said leakage-water chamber also having a leakage water-containinG space and a gas space therein, and including a line mutually connecting the gas spaces of said water storage tank and the leakage-water chamber. 